Lock for small arms



Feb. 23, 1932. E. STERNBERG LOCK FOR SMALL ARMS Filed April 4, 1930 2Sheets-Sheet Feb. 23, 1932. E. STERNBERG LOCK FOR SMALL ARMS Filed April4, 1930 2 sheets sheet 2 Fig.5

. p f f M w/Wm" h m r 8 h H m 9 9 M/J J n F9 t m Patented Feb. 23, 1932EMIL STERNBERG, OF BREMEN, GERMANY LOCK FOR SMALL ARMS Application filedApril 4, 1930, Serial No. 441,473, and in Germany April 9, 1929.

The invention relates to a rebound lock for small arms, and its objectis to afford the possibility of a deeper bend in the cocking piece, thusensuring absolute safety of the lock without prejudice to the gentlenessof the ull off. 'In addition, the intention is to construct the lock sothat it may be stripped without the aid of auxiliary tools.

A small arm lock is already known in which 1) a pawl actingas a powertransmission device transmit-s to the sear a part only of the force ofthe mainspring acting directly upon it. In the known construction, themainspring is secured at itsapex by a pivot in the lock 35 plate, sothat it cannot transmit its full striking force to the cocking piece. Asa consequence, considerable cocking is required, which slows down thefiring considerably. The pawl acting as a power transmission de- 23 viceis mounted between the pivot of the cocking piece and the pivot of thesear, which gives a very long lever arm to the nose end of the sear, andconsequently results in a very harsh and stiff pull off. The safety ofthe lock is rendered questionable by this device.

According to the present invention, despite a deep bend in the cockingpiece, a rebound lock with a very gentle pull on is obtained by the useof the known transmission device in the form of a bridge, the bridgebeing placed loosely, with its forked end embracing the cocking piece,on a retaining pin in the lock plate, the said bridge by co-operatingwith the mainspring, which is placed 5 with its apex resting freelyagainst a stop pin on the lock plate, holding together all the movableparts of the lock, the said parts being secured to the lock plate by thechain which is passed through a slot in the retaining pin. The oneforked end of the mainspring then rests in the known manner against thechain pin of the chain, and the second forked end of the mainspringrests hingedly in a depression in the bridge. In the new lock,therefore, the bridge and cocking piece are mounted on the same pivot,so that, in order to afford the possibility of a gentle pull 011', thenose end of the sear may be made very short. Absolute safety of the lockis also secured by making the bend in the cooking piece very deep. Thelock may be stripped very simply without the aid of auxiliary tools.After the spring has been released from its elastic mounting, the otherparts'come loose of themselves.

'The sear is preferably guided in a groove in the lever end of thebridge.

According to the invention, the bridge may at the same time hold the endof a leaf spring of an indicating device, while the other end of thebent leaf spring, with the pin secured'thereto, is actuated by the camon the underneath part of the'cocking piece, so that when the pinprojects laterally from the lock plate, it indicates that the lock is inthe cocked position.

A lock constructed according to theinvention is shown by way of examplein the accompanying drawings, in which,

1 Figure 1 is a side elevation of the uncooked Figure 2 is a view of thesame'fromabove.

1 liigure 3 is a side elevation of the cocked Figure 4 is asideelevation of the-lock plate with the parts riveted thereto.

Figure 5 isa view of the same from-above.

Figure 6 is the bridge in three views.

Figure 7 is the indicating pin withthe leaf springin two views.

Figure 8 is the mainspring viewed from above, and a side elevation ofthe upper limb of the m'ainspring.

Figure 9 is the sear in'two views.

Figure 10 is the cooking piece in two views.

Figure 11 is the chain in two views.

Figure 12-is the lock in perspective.

To the lock plateau of the small arm lock, which is in the form of aside lock, are-secured a retaining pin 5, a pin 0 and a stop pin (Z. Thebridge k (Figure 6), and in the fork of the bridge, the cooking piece(Figure 10) are mounted rotatable about the retaining'pin-b. The chain(Figure 11) is pivoted at e in the fork of the cooking piece, thepin fof the said chain being situated in the forked'end g of the limb h ofthe mainspring (Figure 8). The free end i of the limbjof the 'mainspringlies in a depression of the bridge. The apex of the mainspring restsagainst the stop pin (Z. The sear (Figure 9) is made in the form of adouble armed lever, mounted rotatable about the pin 0, and is held bythe side walls m of the groove a in the free end of the bridge. The end0 of the shorter lever arm p may engage in a bent g of the cookingpiece. One end of a leaf spring 1" is pressed against the lock plate bythe bridge. A pin 8 is fixed to the other ent of the leaf spring. Leafspring and pin together act as an indicating device.

The pin 8 is pressed by a cam t on the under portion of the cockingpiece through a hole in the lock plate, and thus indicates in a mannervisible from the outside the cocked position of the lock.

After the shot has been fired, the cam releases the spring with the pin,the latter disappearing within the lock plate.

When the lock is to be cooked as shown in Fig. 3 the cock piece pivotedon pin 2') is turned arcuately so that its outer portion will move fromthe position shown in Fig. 1 to that of Fig. 3. The turning movement ofthe cock piece in turn causes the cam t located on the under portion ofthe cock piece to laterally push the indicating pin so that the part 8laterally projects from the cock piece. At the same time, the chain 7and the bridge 70 approach toward each other such that the ends f and 2'respectively, of the main spring parts It and j are brought closelytogether so as to increase the tension within the main spring. The upperportion of the bridge 70 being grooved, the end i of spring j slidesalong its upper surface and then held into final position while theunder portion of the bridge slides over the sear p. The nose piece 0 ofthe sear p is brought up against the side (7 of the rounded portion ofthe cock piece. In order to reduce the recoil of the lock to a minimum,it is to be noted that the bridge and cooking piece are mounted on thesame pivot. lVhen the tension on the spring arms h and j is released,nose piece 0 of the sear being relatively short, slides very easily awayfrom the bend g of the cock piece without any danger of resisting thepull of the trigger to release the tension of the different parts withinthe locked units. Furthermore, the nose piece 0, after being releasedfrom the part 9 of the cock piece, slides over the broad bend of thecock piece, thereby eliminating any excessive pull otherwise required toset off the lock.

All the movable parts of the lock are pressed against one another by themain spring, and hold one another together mutually by virtue of theirforked construction, especially that of the bridge. The whole is heldsecurely at the lock plate by the chain which moves in a slot in theretaining pin.

I claim:

1. A rebound lock for small arms, in which a power transmission device,for example a bridge, transmits to the sear a part only of the force ofthe mainspring acting directly on the said device, characterized in thatthe transmission device constructed in the form of a bridge, is placedloosely with its forked end embracing the cooking piece on a retainingpin on the lock plate and with the cooperation of the mainspring, oneforked limb end of which rests hingedly in the known manner on the chainpin of the chain, while the second similarly forked limb end of the saidmainspring rests hingedly in a depression of the bridge, holds all themovable parts of the lock together, the said parts bein secured to thelock plate by means of the chain passed through a slot in the retainingpm.

2. A small arm look as claimed in claim 1, characterized in that thesear is guided in a groove located at the lever end of the bridge.

3. A small arm lock as claimed in claim 1, characterized in that thebridge holds securely one end of the leaf, spring of an indicatingdevice, while the other end of the bent leaf spring, with the pinsecured thereto, is actuated by the cam on the under portion of thecooking piece, such that when the pin projects laterally beyond the lockplalte it indicates the cocked position of the loc z. 7

In testimony thereof I have signed my name to this specification. v

EMIL STERNBERG.

